just got a wort chiller (copper coil deal) second batch ive cooled with it, and although i only use it to cool three gallons it has taken about 45 minutes to cool each batch, which seems insanely long. Should i be reducing the flow perhaps?

You need to paly around with the flow but the most important thing is to move the chiller constantly otherwise it creates a "cool" zone around itself and the rate of heat transfer significantly declines. I'm paranoid about sanitation so I have a lid with a hole cut into it that the chiller barely fits through and then just rock it constantly. I have 6g down to ~70F in <20min, 30min to get to 56-58F. I am blessed though with 54F tap water this time of year.

Higher flow always means more cooling, the only tradeoff is the water usage - you will never get BETTER chilling power by turning down the flow - better efficiency perhaps, but not faster chilling. Just like these other guys, I cannot stress enough the importance of stirring. It can make the difference between chilling in 45 mins vs. 15 minutes.

If you want a dramatic example, while chilling, once the outlet water from the chiller has grown cool (but the wort is not done chilling), give the wort a stir while feeling the outlet water - it'll immediately heat up.

You'll make a huge difference if you stir it every 5-10 minutes at least, so the wort is always at least slowly moving - and even more difference if you can keep it stirred constantly (though usually this is done by a recirculating pump or motorized stirrer, rather than by hand)

Here is what i do, this get 12 gallons down to pitching temps in ~ 15 min with my 50' 1/2" Copper Immersion Chillier (IC)

First i run about 15 gallons of tap water through the IC and while this is occuring i grab onto the IC and move it up and down (preventing the cool zone around the coils). The first 15 gallons comes out of the IC pretty warm so i just save this in my HLT for the next brew/clean up of this brew.

Then i run 4 more gallons of tap water through the IC, and collect this in brew bucket. i add all the ice from my ice maker in to this water. I just keep moving this same water through the wort from one bucket to another, until they reach equilibrium around 68 degrees. I use a cheap aquarium pump to move the water from bucket to bucket through the IC.

This water is also saved and used around teh house. I dont waste in water used for cooling. Last week i washed my car with cooling water.

The tap water temp is the single most important factor in figuring out how fast you can cool your wort and what the practical minimum temperature you can expect. If the tap temp is 65F, that is also the lowest possible temp you'll ever get the wort without invoking ice. Not only that, as your wort temp approaches the coolant temp, it takes longer and longer to drop 1 degree because the delta is smaller. If your tap temp is 80F+, you'll NEVER get down to pitching temps even if you run the water for 24 hours.

I used to worry about wasting water, but now I just run the water full blast and save the water in a bucket and dump it into my washing machine. Works great, I always brew on the weekends, so now I always have clean clothes for the work week.

I stir the entire time I have the water running, it only takes about 5 minutes to get the water down below 75. I do have 60 deg tap water, but the key is to stir it, the wort had to come into contact with the chiller and the best way to do that is to stir it.

I'm not totally worried about hot side aeration, but to be safe I'm really gentle with the stirring until the wort gets below ~120° or so. Once I'm in double digits, I'll stir pretty aggressively; after all, it's just aerating the wort at that point.

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